1. Field of the Invention
This invention relates to an image processing apparatus and method for carrying out image processing according to the characteristics of an image.
2. Related Background Art
Heretofore, a printer driver which is software for controlling a color printer has carried out the processing of color conversion from RGB (red, green and blue) colors to CMYK (cyan, magenta, yellow and black) colors which can be printed by the printer as well as pseudo gradation processing or color compensation processing for all image data to form output image data, no matter whether all the areas of an output image are colored or not, that is, whether or not they include a monochrome area, and has outputted the image data to the printer for color printing, in accordance with a drawing order when it receives the drawing order for an RGB color image from an application program for color printing.
However, in the above printer control, when the output image is partially colored and includes a monochrome area, the printer driver has performed the processing of color conversion into CMYK colors and pseudo gradation or color compensation processing for image data on the monochrome area as well. As the result, when an image includes a large monochrome area, there are such problems as low efficiency and low processing speed.
Similarly, when gray scale printing is performed with a monochrome printer, color conversion processing from RGB colors into gray and pseudo gradation or color compensation processing have been performed for all image data, no matter whether or not an output image is partially gray, that is, whether or not it includes a solid black or white monochrome area and hence, there are the same problems, that is, low efficiency and low processing speed.
In view of the above problems, it is therefore an object of the invention to carry out image processing efficiently by processing an image depending on whether an image of interest is a monochrome image, a color image having a larger number of colors than a predetermined value, or a color image having a smaller number of colors than the predetermined value.
Another object of the invention is to identify the number of colors at a high speed by analyzing a drawing order to identify the number of colors.
A further object of the invention is to carry out image processing efficiently by determining whether each predetermined area is colored or not for image processing.
Still another object of the invention is to obtain the good results of image processing irrespective of image processing mode.
To attain the above objects, the present invention provides an image processing apparatus comprising:
input means for inputting image data constituting an image to be output;
determination means for determining whether the image to be output is a monochrome image, a color image having a number of colors larger than a predetermined value or a color image having a number of colors smaller than the predetermined value; and
image processing means for carrying out image processing on the input image data based on the result of the determination.
The present invention also provides an image processing apparatus comprising:
input means for inputting a drawing order for forming an image to be output;
identification means for identifying a number of colors of the image to be output by analyzing the drawing order; and
image processing means for carrying out image processing on the image to be output based on the number of colors.
The present invention further provides an image processing apparatus comprising:
input means for inputting a drawing order for forming an image to be output;
identification means for analyzing the drawing order and identifying whether a predetermined area of the image to be output is colored or not; and
developing means for developing the image to be output based on the drawing order, for carrying out image processing on the predetermined area of the developed image based on the identification.
The present invention still further provides an image processing apparatus comprising:
input means for inputting image data indicative of an image;
determination means for determining whether color image data is contained in each predetermined area of the image; and
selection means for selecting a color image processing mode or a monochrome image processing mode for each predetermined area based on the result of the determination,
wherein there is conformity between the color image processing mode and the monochrome image processing mode in the processing result for a predetermined color.
Other objects, features and advantages of the invention will become more apparent from the following description when taken in conjunction with the accompanying drawings.